Quentin Peter

PR: drop cloudpickle

1

## Description of Changes * [ ] Wrote at least one-line docstrings (for any new functions) * [ ] Added unit test(s) covering the changes (if testable) * [ ]...

Can not use Spyder 6 with old conda (4.8.3)

3

### Issue Report Checklist * [ ] Searched the [issues page](https://github.com/spyder-ide/spyder/issues?q=is%3Aissue) for similar reports * [ ] Read the relevant sections of the [Spyder Troubleshooting Guide](https://github.com/spyder-ide/spyder/wiki/Troubleshooting-Guide-and-FAQ) and followed its advice...